Lubricating pump



July 15, 1952 G. NEMETZ LUBRICATING PUMP 2 SHEETSSHEET 1 Filed July 28.1947 Fig? A INVENTOR. Guafiavflmeiz, mceweab,

15, 1952 NEMETZ 2,6@3,l5

LUBRICATING PUMP Filed July 28. 1.947 2 SHEETSSHEET 2 rmm a ml IN V ENTOR.

Patented July 15, 1952 HTED s LRICATING PUMP Gustav Nemetz, deceased,late of Vienna, Austria,

by Valerie Nemetz, administratrix, Vienna,'Austria, assignor to Alex.Friedmann, Kommandit- Gesellschaft, Vienna, Austria Application July 28,1947, Serial No. 764,144 In Germany November 4, 1943 Section 1, PublicLaw 690, August 8, 1946 Patent expires November 4, 1963 Way of a dropnozzle, and a delivery piston forcing the oil distributed to thelubricating point, and consists essentially in that the working cylinderof the distributing piston is formed in a member which moves when thepump is operated, while the operation of the distributing piston isderived at least in part from the movement of the member containing thedistributing piston. Such a design produces an advantageousconstruction, and in simple manner permits the designing of a movingmember necessary for the operation of the pump and serving at the sametime to operate the distributing piston, or on the other hand theutilization of the member forming the cylinder of the distributingpiston for some other additional function. Thus, according to theinvention, this member is preferably designed as supply piston, whichsupplies the lubricant under pressure to the Working chamber of thedistributing piston, and thus, even in the case of a lubricant which isviscous or of thick consistency, ensures perfect filling of the workingchamber of the distributing pump.

According to the invention, the arrangement is such that the suctionstroke of the distributing piston is forcibly brought about or supportedby the pressure of the oil supplied to its working chamber by the supplypiston, so that under any conditions the suction stroke of thedistributing piston is ensured. The distributing piston can be compelledto perform the delivery stroke by a stop which is adjustable for thepurpose of varying the amount distributed but immovable during theworking cycle of the pump, and against which it is brought by themovement of the supply piston. The distributing piston may, however, forthe purpose of forcibly bringing about its delivery stroke be connected,in such manner as to be unable to move axially, to the fixed regulatingdevice provided for the adjustment of its stroke. The pump action of thedistributing piston is then obtained by the movement of the member ofthe pump unit, such as the supply piston, which contains its workingchamber.

In order to permit the escape of the excess oil forced into the workingchamber of the distributing piston from the working chamber of thesupply piston during the latters compression stroke, a lateral pressurerelease aperture is conveniently provided from the bore containing thedistributing piston. This aperture is opened by the dis- 13 Claims. (Cl.103-5) tributingpiston during the "suctionstrokawh'e oil under pressureflows into its working chamber, and the distributing piston slides overand closes it during its delivery stroke. During the suction stroke,therefore, the working chamber of the distributing piston is floodedwith oil under pressure, and it is impossible for its workingchamber'not to be completely full of oil at the commencement of thecompression stroke andfor inaccuracies in.

the delivery of the pump unit to occur.

In the drawing the invention is diagram-- matically illustrated with theaid of examples. Figs. 1 and 3 show two' vertical cross-sections throughlubricating pumps having pump units designed in accordance with theinvention, while Fig. 2 shows details of the upper end of thedistributing piston of Fig. 1 ma section at'rightangles to the sectionalplane of Fig. 1.

The pump units in the example illustrated in Fig. '1 are driven by aneccentric shaft l, which carries one eccentric disc 2 for each pumpunit. On each eccentric disc 2 is mounted a double lever3, the forkedend 4 of which encloses arod 5 which is stationary in the pump housing,so that "that lever end is guided as the eccentric shaft l turns,whiie'its other end, which is in the form? of a spherical pin 6,describes a reciprocating movement. The spherical pin 6 thus drives theappertaining pump unit by engaging in a transverse bore 1 in a bolt 8guided in abore 9 in the body ll] of the pump unit. The pointofapplication of the spherical pin 6 lies within the cross-sectionof thebolt.

The bolt 8 is thus moved to-and-fro' with a uniform stroke, and from itboth the delivery piston II and the distributing piston [2 of the pumpunit derive their movements. The delivery piston II, which lies in abore [3 parallel to the bore 9 in the body In, is immovably connected bya crosshead [4 to'the end of the bolt 8 projecting-from the bore 9. Thecross-head l4 encloses the end of the delivery piston I I, with agoodfit,'between the shoulders of a groove [1, and with a second forksimilarly encloses the end of the bolt 8 by engaging in lateral recessestherein between the surfaces l5 and 16 (see also Fig. 2). Every axialdisplacement of the bolt 8 is therefore accompanied by the same axialdisplacement of the delivery piston l I.

In addition a blind bore i9, into which the distributing piston l2is'fitted, is bored into the face of the boltend 8 which carries thecross-head I l. The distributing piston has, in an axial bore. 22, a

spring-loaded overflow valve 20, which releases.

when a corresponding pressure occurs in the bolt as far as a groove-likecavity 58 in the sur- 1 face of the bolt. In the hollow surface of thecylindrical bore 9 is provided an axially parallel cavity 59 extendingfrom :its lower'endupwards to a certain height. The cavities 58 and '59"form a control, the purpose below.

In addition, the pressure passag'e 29 leadsfrom the working chamber 2!of the distributing piston I2 radially out of the bolt 8, and dischargesto the surface of the bolt into a cavity E'Ipwhich connects with theopening of the part 29 of the pressure passage, which continues inthebody H] of the pump unit, in the illustrated highest posi non-or thebolti8. .Aco'nt-rolfor thepressurepas= rsage z29, .29 is therebyJformed. The'bore 129' :crosses the cylinder bore 13411 which lies thedelivery piston II. The latter has a groove at, which connects thevpartsof the-portion29 of the pressure passage which "are interrupted by*the'bore [3. The groove '30fis'of'such a'width' that it controls thepassage through the pres sure passage '29 j' in the "same manner as isdone of which 'will'be explained by the movements ofthebolt cavity '51relatively to the aperture of the portion 29' of the pressure passage.The groove 30 thus has the smallest possible width. This alignment ofthe passages, in'conjunction'with the groove 39, is advantageous forreasons of manufacture, since in this way theaxes .ofb'oth" the "boresSand l3 and the pressure "passage 29,229, andthat of the drop nozzlei'canl1iein one-plane.

The body to o-fithe pump unit is fastened to the cover .3liiby means of.the screws Mandthe *outlet'nipple .33. A plurality of pump units canbeimounte'd side by Side on the same "cover :31 'A'ibowl iifi', to whichis connected a bowl portion "36' in the body Illof 'ea'ch pump unit; is:pro-

vided in the coverv 3|:to collect the drops falling from the 'nozzle'35. The bowl parts are separatedifrom'one another'by a part '38,designed after the style of Ta sieve, of a packing plate 38disposedbetween the bodies l'll'ofthe'pump units and the cover (H. Theinsertion.aperature 54 in the pump housing 31'is'clos'ed by means-oftiie cover'3l.

From the bowl 36' a suction passage '36" leads to -the working chamber34 of the delivery piston H,- and is'b'ounded atthe bottom by a controlpiston '3 9' which is guided'in the' cylinder bore l3 and 'actsafter themanner of'a'valve. The control piston iiil is pressed upwards by thespring '40, so that it constantly seeks to'slide over and close thedelivery passage '42 leading out of the bore 13. This passage iscontinued by'th'e connecting nipple '33 in the direction of thelubricating point. 'Thehighestposition of' the control piston 39 isdetermined 'by a collar 4|. A projection 43 on "the lower end of thebolt 8' engages beneath this "collar in such a manner that, as the bolt8 moves upwards, the control piston '39 is carried with it in theevent'of the failure of thespri'n 'liband closes the pressure passage42. The bottom end ofthe bolt; 8 "andthe spring-loaded endof the controlpiston 39 both'lie in the hollow space 44 of 'a 'cap'46, which istightly fastened to the body It ofthe'pump uni-t by'means of'screwsflfi, and

- which forms the working chamber for the b01138 acting as supplypiston.

4. The pump unit Works as follows: When the shaft l is driven in anyrotational direction, the bolt 8 is moved up anddown with uniform strokeby the "sphericalpin '6 of the lever 3, and by means of the cross-head14 carries with it the delivery piston II, which in the positionillustrated, is just beginning its delivery stroke from top to bottom.The bolt 8 penetrates with its lower end into the working chamber '44,and first forces the oil back through the aperture -'41 into the oilstorage vessel of the pump housing 31, until its control edge 48 coversthe aperture of the bore 41, whereupon the oil,

in the working chamber 44 is placed under superatmospheric pressure. Inthe meantime, the cavity 5'! on the bolt 8 has moved so far down thatpassage through the pressure passage 29,

28" is interrupted, whereupon the groove-like cavity 58 connects withthe cavity 53 of the bore 8, so that the chamber 44 is brought into com--munication with the working chamber-2| o'f'the distributing piston 12by way ofthe cavities 59, '58, the longitudinal groove-24, and thetransverse passage 23. The oil under pressure then flows i out of theworking chamber ,44 into the working chamber 2|, and forces thedistributing piston i2 upwards out of the blind bore I 9, until itsshoulder l8 bearsagainst the lower surface W of the cross-head H. Theexcess amount of oil iorced out of-the'working chamber into the workingchamber 2| escapes through the overflow valve 29 and the outletaperture'22 and,

lubricating the driving parts of the pump'uni-t onits wayi-flows off. r

Simultaneously with the bolt 8, the delivery piston H also movesdownwards and penetrates into :its working chamber 34-, enclosingbetween its lower :faceand the upper face of the control piston 39 ana-mount of oil which, overcomingthe power of the-control pistonspring-40 it" pushes down together with the control piston 39, until theupper facexof the control piston 39" arrives beneath the aperture of thedelivery passage 42, through which the oil is forced through the nipple'35' to the lubricating point. The downward movement of the controlpiston. with'the c ollar 4| is limited by the shoulder 50011 the captrol piston 39- and its guide 13 passes backinto the bowl 36 by :way ofthe groove 5| and'the bore 52. i 7

During their suction stroke, the bolt "8 and the delivery piston {I moveupwards. A negative pressure is produced'in the working chamber 44 ofthe bolt 8 and, as long as said chamber remains incommunication with theworking chamber 2| of the distributing piston 12, also in the latterchamber, until the control edge '48 of the bolt 8 slides upwards overthes'uction aperture 4i and opens it. Thereupon oil is sucked intothe'worki'ng' chamber 44 from the storage'vessel in the pump housing 31,by way of the suction passage '41. r

In order to prevent the distributing piston 12 from being'sucke'ddownwards into the blind bore '19 by the negativepressure in theworking'chamber 44, a brake is provided for the distributing piston l2,which consists of a clamp spring-6i! held in'a groove in the cross headl4 (see Fig.2). Shortly after the commencc'ain'entof'the' suction strokeof thebolta, communication between'the cavities 59 and 58', and hencecommunication between the working chambers 44 and 2!, is interrupted.Towards the end of the-suction stroke the cavity 51, into whichdischarges "the Oil passing downwards between the con pressure passage29 which'leads out of the working chamber 2I' comes into communicationwith the portion 29' of the pressure passage. Thereupon, the upper endof the distributing piston I2 strikes against the regulating screw 53and, depending on the setting of the regulating screw 53, thedistributing piston I 2 is forced to a greater or lesser extent into theblind bore I9, delivering an accurately measured amount of oil from theworking chamber ZI, through the passage 29, the cavity 5?, the portion29' of the pressure passage, and the groove 32 in the delivery piston II, to the drop nozzle 35. Since this delivery takes place during theperiod of quite low load on the driving parts of the pump unit (at thistime only the suction strokes of the bolt 8 and delivery piston I I areb eing carried out) and the working chamber 34 is not under pressure, noinaccuracies in the delivery of the distributing piston I2 on the scoreof elastic deformations of the pumpunits can occur.

In the position of the r gulating screw 53 illus trated in Fig. i, thereis no delivery stroke for the distributing piston. In order to obtainsuch a stroke, the regulating screw 53 must be screwed down as required.In this manner regulation'of the delivery amount of the pump unitbetween zero and a certain maximum value is possible.

- From the drop nozzle 35 the oil falls into the bowl 38 of the cover 3!and, purified by the sievelike part 38' of the packing plate 38 lyingbetween the body Ill of the pump unit and the cover 3!, flows into thebowl part 35' and thence by way of the suction passage 35" into theworking chamber 34 of the delivery piston I I,

Owing to the force of the spring 40, the c0n== trol piston 38 alsofollows the upward suction stroke of the delivery piston II. If thatforce should not be suflicient for the purpose, it is pushed upwards bythe projection 43 on the bolt 8, which bears from below against thecollar ll. The control piston, in moving upwards, slides over and closesthe delivery passage 42,

As can be seen. the pump unit is of very simple design. The fittingbores for the pistons are disposed parallel to one another in the bodyIt of the pump unit, and can therefore be made with the requiredaccuracy at little expense of labor. The assembly of the individualparts is also a simple task, mistakes being impossible.

In Fig. 3 is illustrated a similar lubricating oil pump unit designed inaccordance with the in vention. Communication between the workingchamber 44 of the bolt 8 working as supply piston and the workingchamber 2! of the distributing piston I2 is in this case established bya bore 26 in the bolt 8, which contains a check valve 21 openingupwards, the seat of which is formed by a screw cap 28. A bore 25 leadsradially from the bore 26 to the lateral longitudinal groove 24 in thesurface of the bolt, so that controlled communication is establishedbetween the working chambers 44 and 2I by way of the passages 23, 24,25, and 26 and the check valve 21. p

The distributing piston I2 is joined in this embodiment to theregulating screw 53 by a claw connection which prevents axialdisplacement, so that it is held fast relatively to the bolt 8 in everyposition of the regulating screw 53, and performs in the blind bore I9the same stroke as the bolt 8 in the bore 9 of the body ID of the pumpunit.

As an overflow for the excess of oil delivered during the compressionstroke from the working chamber 44 into the working chamber 2 I, thebolt 8 carries a lateral aperture 56, which is passed over and closed bythe lower face of the distributing piston I2 during the suction strokeof the bolt 8, whereupon it performs its delivery stroke. In order thatoil cannot be sucked back into the working chamber H from the pressurepassage 29, 29 at the commencement of the suction stroke of, thedistributing piston I2, as long as the pressure passage is still open, aspring-loaded check valve 6| is provided in the part 29' of the pressurepassage. This also prevents oil from being delivered through thedropnozzle 35 before the overflow aperture 56 is closed by the.distributing piston I2 during the latters compression stroke. Except forthe above described details, the pump unit illustrated in Fig. 3 is ofexactly the same design as that illustrated in Fig. 1. It works in thefollowing mannerr The bolt 8 moves downwards out of the positionillustrated at the beginning of the compression stroke. The distributingpiston I2 held fast by the regulating screw 53 is drawn out of the blindbore I9., If there should be produced a greater degree of vacuum in theworking chamber 2|, the check valve 27 will open and oil will flow intothe working chamber 2! through the passages 23, 24, 25, and 26, whilethe check valve BI in the pressure passage 29' remains closed. As longas the control edge 48 of thebolt 8 leaves the suction passage 41 free,oil is forced 'out of the working chamber 45 through the passage 41.After the closing of the passage 41, the oil is forced out of theworking chamber 45, after the lifting of the check valve 27, through theconnections 23, 24, 25, and 26 and into the working chamber ii of thedistributing piston. In the meantime, however, the distributing pistonI2 has moved above the lower edge 62 of the lateral aperture 56 of thesupply piston 8, and the oil therefore flows through the overflowaperture 56 into the storage vessel of the pump housing 31, lubricatingthe driving parts.

During the suction stroke of the bolt 8, negative pressure is firstproduced in the working chamber 44, but owing to the check valve 2'!this cannot extend to the working chamber 2| which is full of oil. Afterthe cavity 51 has come into communication with the part 29' of thepressure passage, the distributing piston I2 slides over the edge 62and, towards the ends of the suction stroke of the bolt 8, forces theoil enclosed by it in the working chamber 2| to the drop nozzle '35 byway of the pressure passage 29, 29' and the check valve 6|. From thedrop nozzle the oil drops into the bowl 36, from which it flows to theworking chamber 34 of the delivery piston Ii. What is claimed is: v '1.A lubricating pump comprising a pump housing, a drive member therein, atleast one pump unit mounted in said pump housing, each pump unitincluding a body, an intake piston mounted in the body and in drivingconnection with the said drive member and driven in reciprocatorymovement, means connected to the body and providing a working space forthe said intake piston, said pump unit body having an inlet bore intothe said working space, said intake piston having a cylindrical bore, adistributing piston mounted in the said cylindrical bore, an adjustableabutment in the said housing, which. coacts with the said distributingpiston to press the same inwardly into the said cylindrical bore whenthe said intake piston is moved toward the said abutment, a channel insaid intake piston extending from the said working space to the saidcylindrical bore through which the lubricant is forced from the saidworking space to the said cylindrical bore, a feed piston "providedinthe body for said feed piston, a lubricant :line' fromv the-saidcylindrical bore to the last-mentioned working space through which. the

lubricantis conveyed. in measured quantities. to

the-.saidfeed .piston, anda-lubricant outlet in connection with thelast-mentioned working space through which the said feed piston ejectsthe lubricant.

-2..A lubricating pump according to. claim 1,

in which the said distributing piston. is secured 4. Alubricating pumpaccording to claim 1, in: which the cylindrical bore is providedwith. a

discharge opening for excess lubricant whichis closed by the saiddistributing piston at the beginning. of its feed stroke.

5. A lubricating pump according to claim. 1, in which the lubricant linebetween the cylindrical bore and" the last mentioned working spaceincludes a check valve and a drop nozzle.

6. A lubricating pump according to claim .1,

.in'which the lubricant line includes a cavity in the said intake pistoncommunicating with the said cylindrical bore, a drop nozzle in the saidline, and the body of the pump unit having a channel which leads fromthe said intake piston to the said dropnozzle and which. also forms a."pa-rtof the lubricant line between the said cylin idrical: bore and thelast mentioned working space, the said cavity and the last mentionedchannel being'arrahged so that they come into registra-- tion with eachother only toward the end of the suction stroke of the said intakepiston.

'7. A lubricating pump according to claim 1, in which the said feedpiston is arranged so that it crosses the lubricant line between thesaid cylindrical bore and the last mentioned working I space, andthe'said feed piston having a groove which controls the flow oflubricant through the said line.

8-. A lubricating pump according to claim 1,

in which a check valve is positioned in the chann'elin the intake'pistonextending from the first 'mentioncd working space to the saidcylindrical bore.

9-. A lubricating pump according to claim 1,.

in which the said intake piston and the said feed, piston are arrangedparallel to each other and connected with each other at their upperends.

10. A lubricating pump according to claim 1, in which the pump unit bodyhas a cylindrical bore for receiving the said intake piston, said borehaving a cavity which forms an extension -of the Working space of theintake piston, a

channellin. the said intake piston terminating in a cavityat theperiphery of the said intake piston, the two mentionedcavitiesperiodically registering witheach otherfor the control ofthecommunication between the first mentioned working space for theintake piston andthe cylindrical bore whichreceivcs-the distributingpiston.

11. Alubricating pump as claimed inclaim .1, inwhich means is providedin the lubricant line for controlling the passage of the lubricant tothe lubricant outlet, said means comprising a spring loaded pistontraversing theline adjacent the outlet.

.12. Alubricating pump asclaimed in claim .11, in which av projection isprovided, on the lower end. of the intake .piston and. cooperates with.the

spring loaded. piston to insure of operation'of the latter in. event ofspring failure.

13. A. lubricating pump comprising a: pump housing, a drive membertherein, a pump unit comprised in part by a body mounted. in saidhousing and having a pair of piston receiving bores therein, said pumpunit body having .a pressure passage extending from the first borethrough the second bore, a delivery-piston reciprocable within thesecond bore and controlling the flow of fluid therethrough, an intakepiston reciprocable within the first bore'and having an'axialcylindrical bore therein, a port adapted to communicate said axialcylindrical bore with the inner end of the pressure passage in the pumpbody and a groove adapted to communicate the axial bore with a source offluid lubricant,

said intake piston being driven in reciprocatory' movement by' saiddrive member, a distributing piston reciprocable Within the axialcylindrical bore in the said intake piston and adapted. to

REFERENCES CITED The following references are of record'in'the file ofthis patent:

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